Printwear

May '19

For the Business of Apparel Decorating

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2 0 1 9 M A Y P R I N T W E A R 4 9 tated by the manufacturer. Also, in most cases, the screen tension should be relatively tight, and the suggested screen mesh count for the ink being used should be adhered to. Ink: Make sure the correct ink is selected, such as low bleed for polyester fabric, or maybe general purpose for a poly/cotton blend, etc. In addition, we need to assume the squeegee durometer is within the correct range for this application. When the ink is applied with these correct tools, it should work. However, it could very well fail if the relationship of these tools are incorrect. To better our chances of success, the following printing rules should be followed on a manual press: 1) With the screen disengaged from the platen, the ink should be flooded with enough force to push the ink into the stencil in the screen past the mesh. This is the point where there is the least resistance from the mesh to allow the ink to fill the area. If this action is not performed, the printer is forced to print with perfect pressure to achieve an adequate print; a nearly impossible feat to achieve and maintain. 2) Lower the screen onto the substrate and print with the least amount of pressure to allow a clean print. This is all relative to the ink's thickness, however, and it is a good idea to do a few practice strikes to get a feel of what this pressure should be. A sharp-edge squeegee will aid in this action. If too much pressure is used, the ink will not show as opaque and the surface will not be smooth. 3) As the ink is printed, the off-contact should be adequate enough to allow the screen to separate from the printed im- age as the squeegee passes. This action is usually referred to as a peel. This is also relative to the screen tension; the tighter the screen, the less off-contact is needed. Don't be afraid to increase this off-contact level for looser mesh or thicker ink. If the screen does not separate from the image as printed, the screen can become attached to the print, thus lifting the fabric or creating an undesirable surface. In some cases, the ink can be lifted back off the substrate giving the appearance that the ink isn't clearing the mesh. It's best to print with the least amount of pres- sure, but still al- low the ink to clear the mesh.

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